Liquid spray systems attachable to powered farm vehicles or other vehicles towable thereby are well known to the agricultural industry. A typical construction involves the attachment of a pair of spray booms to the rear of a powered farm truck or vehicle (or alternatively to the front or rear of a towed farm vehicle), mounting a large supply tank on the vehicle body carrying the booms, connecting chemical tank hoses to spray nozzels on each boom and dispensing fluid fertilizer, chemicals, etc. from the tanks to crops or the farmland.
Very many spray boom assemblies and mountings therefor have been provided in the past for mounting and transport on tank vehicles of the character described. The basic purpose of such boom provision is the spreading of liquids along a path of substantial width in the direction of the movement of the vehicle. When the spray booms are rigged out for spraying action, they typically extend for a distance very much substantially wider than the width of the vehicle. Accordingly, various mechanisms, devices and structures have typically been provided in such assemblies for not only supporting and positioning the booms in the spraying operation, but also for rigging-in the booms alongside the vehicle for two purposes:
(1) So that the vehicle may transit roads or spaces narrower than the substantial width of the extended boom; and
(2) In order that the vehicle may be stowed or garaged in such smaller spaces.
In the assemblies which include rigging-in capacities, all points along the lengths of the booms must clear the vehicle tires and road surfaces and, typically, permit ingress and egress from the cab of a vehicle by the operator (when the booms are mounted on the powered vehicle).
In the listing of the "Prior Art" hereinafter in this specification, devices having (1) forwardly folding booms (usually rearwardly attached) and (2) rearwardly folding booms (usually forwardly mounted on the vehicle) are listed and disclosed from very early in the art to present time.
Typically, the longer the boom, the more massive the support structure and more expensive the boom handling and rigging structure. As examples of such, reference is made to three relatively recent patents involving quite massive vehicles and massive and complex structural mountings for the boom supports and rigging means. These include U.S. Patents to Widmer, No. 3,887,132, issued June 3, 1974 "Boom Assembly"; Robinson, No. 3,927,832 issued Dec. 23, 1975 for "Horizontal Boom Lift Arms" and Batts, No. 4,138,063, issued Feb. 6, 1979 "Hydraulically Operated Fertilizer and Chemical-Spreading Boom".
What is needed is an effective, simple, manually operated (as opposed to power operated) boom mounting and rigging structure and system which involves a minimum of structure and weight yet effectively mounts the booms outwardly under all the problems and rigors of normal spraying operation and further permits the recovery thereof in handy, effective fashion. Verstility in placement of mounting is also desired. To provide such optimum boom mounting, rigging and handling means with, further, extendable end portions of the booms to provide effective boom length are the prime objects and purpose of this invention.